He is arguing that the force of that regulation falls unfairly on public companies, against whom it can be enforced effectively, and not on individuals starting rumors, who are numerous and hard to track down. That's not a silly claim.
The problem he is talking about is market manipulation. Let's be clear, disclosure is precisely to prevent market rigging by insider trading and indirection (as the notion of a free market depends on all participants having equal information). He's in fact advocating going back to an insider's club and trying to dress it up as the opposite. I don't know if he's just stupid or he thinks the readers are.
